The present invention relates to photosensitive iodonium polymers and to heat curable cationically polymerizable compositions using such photosensitive iodonium polymers in combination with a copper compound as a cocatalyst.
Prior to the present invention, Y. Yamada and M. Ikawara reported the synthesis of phenyl polystyryliodonium salts having the iodonium structure as a pendant group on the main chain, Macromol. Chem. 152, 153, 163 (1972). H.K. Livingston and J.W. Sullivan, J. Polym. Sci. C., 195 (1968) synthesized polymeric iodonium materials by various procedures including the condensation of a dicarboxylic acid and an organoiodosodiacetate. Additional investigations by Y. Yamada, K. Kashima, and M. Okawara [J. Polym. Sci., Polym. Let. Ed. 14, 65 (1976)]reported the reaction of 4,4'-methylene bis(penyliodoso diacetate) with diphenylmethane resulting in the production of an oligomeric iodonium salt.
The present invention is based on our discovery that high molecular weight resins containing iodonium salt components in the main chain can be made by initially effecting the interfacial polymerization of the diacidhalide of dicarboxydialkyldiphenyliodonium bisulfate of the formula, ##STR1## with diamines, difunctional alcohols, or phenols to produce the corresponding iodonium containing polyamides and polyesters, where R is a C.sub.( 1-8) alkyl radical, X is a halogen radical, and a is a whole number equal to 0 to 3 inclusive. Polymeric photosensitive iodonium salts are provided comprising chemically combined units of the formula, ##STR2## which can be metathesized with an alkali metal or alkaline earth metal hexafluoro compounds of the formula EQU MYF.sub.n, (3)
to produce the corresponding polymeric polyfluoro metalloid iodonium salts, where R.sup.1 and R.sup.2 are selected from C.sub.( 6-14) divalent aryl radicals and C.sub.( 6-14) divalent aryl radicals substituted with 1-4 monovalent radicals inert during interfacial polymerization, Q is a member selected from ##STR3## R.sup.4 and R.sup.5 are the same or different monovalent radicals selected from hydrogen or R radicals, R.sup.3 is a divalent C.sub.( 1-14) hydrocarbon radical or divalent C.sub.( 1-14) hydrocarbon radical substituted with monovalent radicals inert during interfacial polymerization, R.sup.6 is a divalent C.sub.( 2-30) divalent, sodium, potassium or magnesium, Y is selected from B, P, As and Sb, and n is an integer having a value of 4-6.